Contact terminals formed into a stick shape may come into contact with a predetermined target point to electrically connect the target point and a predetermined place (see, for example, Patent Literature 1). The contact terminal in Patent Literature 1 includes a small diameter conductive portion and a large diameter cylinder shape portion that is disposed to surround the small diameter conductive portion. A tip portion of the small diameter conductive portion protrudes from a tip portion of the large diameter cylinder shape portion. A part of the small diameter conductive portion is joined to a part of the large diameter cylinder shape portion. A helical spring is formed as part of the cylinder shape portion of the contact terminal.
Patent Literature 1: JP 2013-53931 A